Thanks all for the recommendations - I have received a very good quote from G&W which does not require a tracker (only over £80k as highlighted by Richard/Peter).
Also, unless you go for less than 5000 miles p/a, it is an unlimited mileage policy with 90 days European travel included.
Headley are now part of another company (Finch?). I contacted them, and they said that a tracker was almost a given - I gave them all my details but it's been over a week now and they've not come back with a quote - which isn't a great customer experience... G&W came back within minutes.
